Diamond-polishing wheel



Patented Apr. 14, 1942 NITED Tes' nIAMoND-Pousnmo WHEEL.

Julius Dinhoier, New York, N. Y.

Application December 4, 1940, Serial No. 368,429

2 Claims. (Cl. 51109) table I by means of the screws 6, said bracketl This invention relates'to polishing wheels of the type employed' for the polishing of diamonds or other gems and the primary object of the invention is to provide a polishing wheel of accurate balance; .one which can be rotated at relatively high speeds without vibration or wobble, and which can be operated for long periods of time without overheating and material wear,

Aand particularly at orV adjacent tthe bear- Polishing wheels as constructed at the present` time, are usually xed on a verticalpshaft or spindle having conical ends supported by and rotative in. suitable bearings. Wheels of this character are rotatedv at relatively high speeds, generally about .250 R.. P. M. and n some cases, at even greater speeds. Since the weightof the wheel, its spindle, the drive pulley and other elements carried on the spindle rest upon the lower conical end of the spindle, wear rapidly occurs at this end; wobble thereafter takes place in the spindle and the wheel thereupon becomes unfit for further use until a new shaft is tted. Due to the conical shape oi the ends of the spindle and the complementary supports inv which these ends fit, it is difcult to lubricate these ends and the surfaces adjacent which they bear, and thus the wear above mentioned, quickly occurs.

It is the primary object of the present invention to so support the vertical shaft or spindle of the polishing wheel that the same does not rest upon ndr is it supported by the conical ends on the spindle. Instead each end of the spindle is provided with shoulder portions which rest against the inner annulus of a ball-bearing which not only co-operates in providing an e'x- `tremely smooth-running polishing wheel at high speed, but prevents the'ends of the spindle from With reference to the drawing, I indicates a l supporting table or similar base, said table being provided with a. circular aperture 2 in which the polishing wheel 3 rotates. The Wheel 3 is secured upon `a vertical shaft or spindle by any suitable means and preferably be being forced thereon under pressure. At 5 is shown a goosevneck bracket secured to the top of the being providedat its upper extremity with-a tion in said boss byfmeans of the set screw 9. The lowerend of the bearing 8 is formed with a cup-shaped member I0 within which a ballbearing II is mounted. Theball-bearing is of the-selfaligning type and includes an outer annulus I2 and inner annulus I3. The ball race I4 is disposed between -the two annuli. At its upper end, the spindle 4 is formed with a portion I5 reduced in diameter and which snugly ts within the inner annulus I3 of the ball-bearing, .the end or terminal of said reduced portion being conical and pointed as indicated at I6.

Locatedbelow the table and secured thereto by the bolts Il is a bracket liiprovided at its lower end with a sleeve portion I9 in which is adjustably secured the lower bearing 20, said bearing being adjustable vertically, or capable of rising and lowering movement in the sleeve I9, by adjustment of the threaded cup 34 on the lowerend 0f the sleeve I9. The set screw 2| secures the bearing 20 in position.` At its upper end thel bearing is provided with a cup portion 22 in which a ball-bearing similar to'that preyviously described and shown in detail in Fig. 2,

is` supported. The outer annulus ofthe lower ball-bearing ish supported uponv an annular shoulder 23 formed in the cup 22, and the lower end of the shaft is formed with a reduced portion 24 iitting in the inner annulus I3. 'Situated adjacent the reduced portion of the spindle d is a shoulder25 which rests upon the inner annulus I3 of the ball-bearing so that the weight ofthe spindle for the polishing Wheel 3 thereon,-

lower portion of the spindle 4 and the ball-bearing.

at the termination of the reduced portion 2d is provided with a conical tip 28 and said conical tip is prevented from frlctional contact with any portion of the bearing 20 sinceV the bearing is recessed as indicated at'29. lThe spindle is driven-at relatively high speed by means of a belt 30 extending from a power-driven pulley, and since the spindle is wholly supported upon and between ball bearings, it will be obvious^- It will be noted that the lower end of the shaft that it can be driven at relatively high speed,l i

without wear, vibration and'wobble. The conical extremities 16 and'29 at the opposite' ends of .the spindle are. out of contact with any portions of the bearing while the device is in operation and'since no wear is imposed'upon these ing 2l. the same being provided with a nipple' 3|.`

, What I claim is:

1. In a diamond-polishing apparatus, a vertically disposed spindle and means for rotating the same,a polishing wheel on said spindle, a brackf et having a portion. extending below the lower end of the spindle, said bracket being provided with an internally threaded bore, a threaded shaft vertically 'adjustable in said bore, means 2. In adiamond-polishing apparatus, a ver l tically disposed spindle and means for rotating` the saine,4 a polishing wheel on'said Spindle. a bracket having an' arm extending below the lower end of the spindle, said bracket being proforV maintaining the. position of adjustment of said threaded shaft, said means'comprising a set screw operative against said shaft the upper end of said shaft being provided` with a cup,.a ballbearing fitted within and wholly retained by said cup, said ball-bearing consisting of spaced concentric annuli with a ball race disposed between vided with a bore, a shaft vertically adjustable through said bore, means for maintaining the position of said shaft within said bore, the upper end of said shaft being provided with a cup, vaball bearing fitted within and retained by said cup, the spindle having a shoulder adjacent to it's lower end .and a reduced portion extending from said shoulder and terminating in a conical end, the shoulder being supported on the ball bearing, the conical end onthe spindle projecting below the lower end of the bearing and constantly maintained from frictional contact with any of the surfaces of the bearing and itssupport whereby wear on said conical end will be prevented and the same will always constitute a true centerl for the spindle.

JULIUS DINHOFER.` 

